The present invention relates to a process for providing reversibly thickened liquids for use in various industrial applications.
In many industrial processes it would be useful to have a process for reversibly thickening a liquid. Examples of these processes are slurry pipeline transport of minerals, removal of the solids produced during the drilling of wells, removal of solids formed during the polishing and grinding of metals, etc. In processes such as these it is advantageous to increase the viscosity of the liquid in order to enhance its solids carrying capacity and to prevent settling out of the solids before they reach their desired destination. The most common method for increasing a liquid's solids carrying capacity is to add a polymer or dispersed solid such as a clay which increases the viscosity of the liquid, particularly at low shear rates. However, in the processes mentioned above it is also necessary to remove the solids from the liquid either to reuse the liquid or to use the solids. This is often done by filtering the liquid from the solids, centrifuging the solids out of the liquid, etc. Unfortunately, the additional viscosity which was useful in transporting the solids also makes the desired separation of the solids from the liquid more difficult. Furthermore, if the viscosity is reduced by the destruction or removal of the polymer or clay used to increase the viscosity of the liquid, additional polymer or clay is needed to restore the liquid's solid carrying capacity. Also, the liquid or solid can be contaminated and interfere with further use by the residue resulting from the use of polymer or clay.
In view of the deficiencies of the prior art, it would be highly desirable to provide a process for improving the solids carrying capacity of a liquid in a manner which can be easily and rapidly reversed in order to aid in the removing of solids from the liquid when desired, and after solids have been removed, to easily and rapidly restore said solids carrying capacity.